Techniques for facilitating electrical design of an energy generation system

ABSTRACT

Systems and methods for facilitating the electrical design of an energy generation system. In one embodiment, a method is provided that can comprise receiving, by a computer system from a user, first information pertaining to an energy generation system to be installed at a customer site. The method can further comprise determining an electrical design for installing the energy generation system at the customer site, where the determining is based on the first information, second information retrieved from one or more external data sources, an electrical data model, and a decision tree that models the electrical design process. An installation diagram can then be generated that illustrates the determined electrical design.

BACKGROUND

The present disclosure relates in general to electrical system design,and in particular to techniques for facilitating the electrical designof an energy generation system.

In recent years, climate change concerns, federal/state initiatives, andother factors have driven a rapid rise in the installation of renewableenergy generation systems (i.e., systems that generate energy usingrenewable resources such as solar, wind, hydropower, etc.) atresidential and non-residential sites. Photovoltaic (PV) systems, inparticular, have been very popular; in 2011, nearly two gigawatts of PVcapacity were installed in the United States, and that number isexpected to double in 2012. The majority of this PV capacity is“grid-connected”—in other words, tied to the utility-maintainedelectrical grid. This allows site loads to be serviced from the grid attimes when the PV system cannot generate sufficient energy due to lackof sunlight (e.g., at night), while allowing energy to be fed back intothe grid at times when PV energy production exceeds site loads (therebyresulting in, e.g., a credit on the site owner's electricity bill).

An important aspect of designing a grid-connected PV system is selectingthe electrical components that enable the system to provide power tosite loads or the utility grid, as well as defining the electricalconnections between the components. Currently, this process istime-consuming and labor-intensive because it must be performed manuallyby individuals who are specifically trained and/or experienced inelectrical system design. Accordingly, it would be desirable to automatethe electrical design process so that it can be performed more quicklyand efficiently, and without requiring substantial training orexperience on the part of the designers.

SUMMARY

Embodiments of the present invention relate to systems and methods forfacilitating the electrical design of an energy generation system.According to one embodiment, a method is provided that can comprisereceiving, by a computer system from a user, first informationpertaining to an energy generation system to be installed at a customersite. The method can further comprise determining an electrical designfor installing the energy generation system at the customer site, wherethe determining is based on the first information, second informationretrieved from one or more external data sources, an electrical datamodel, and a decision tree that models the electrical design process. Aninstallation diagram can then be generated that illustrates thedetermined electrical design.

In one embodiment, the energy generation system can be a solarphotovoltaic (PV) system.

In one embodiment, the first information can be received via a graphicaluser interface.

In one embodiment, the first information can include informationpertaining to one or more direct current (DC) components of the energygeneration system.

In one embodiment, the first information can further include informationpertaining to one or more alternating current (AC) components of theenergy generation system.

In one embodiment, a portion of the first information can be populatedwith defaults retrieved from the one or more data sources.

In one embodiment, the one or more external data sources can be selectedfrom a group consisting of: an Authority Having Jurisdiction (AHJ)database, a utility database, a state database, and a component supplychain database.

In one embodiment, the electrical data model can comprise a plurality ofrules indicating how electrical components of the energy generationsystem may be interconnected, where the plurality of rules conform tothe National Electric Code (NEC).

In one embodiment, determining the electrical design can comprisetraversing nodes of the decision tree, where each node represents aquestion regarding the electrical design or a decision outcome.

In one embodiment, the method can further comprise, for a given node ofthe decision tree representing a question, determining whether thequestion can be answered based on the first information or the secondinformation. If the question cannot be answered based on the firstinformation or the second information, the user can be prompted for ananswer.

In one embodiment, the electrical design can include informationregarding how electrical components of the energy generation systemshould be interconnected.

In one embodiment, the information regarding how the electricalcomponents should be interconnected can include information regardingconduit to be used between the electrical components.

In one embodiment, the installation diagram can be configured such thatAC components of the energy generation system are depicted on one sideof the installation diagram and DC components of the energy generationsystem are depicted on the opposite side of the installation diagram.

In one embodiment, the installation diagram can include a bill ofmaterials.

In one embodiment, the bill of materials can identify make and modelnumbers for each electrical component of the energy generation system.

In one embodiment, the bill of materials can further identify sizes ofwires needed to interconnect the electrical components.

In one embodiment, the installation diagram can be generated using acomputer-aided design (CAD) program, and the receiving and determiningcan be performed by a plug-in module to the CAD program.

According to another embodiment of the present invention, a system isprovided that comprises a processor. The processor can be configured toreceive, from a user, first information pertaining to an energygeneration system to be installed at a customer site; determine anelectrical design for installing the energy generation system at thecustomer site, the determining being based on the first information,second information retrieved from one or more external data sources, anelectrical data model, and a decision tree modeling an electrical designprocess; and generate an installation diagram illustrating thedetermined electrical design.

According to another embodiment of the present invention, anon-transitory computer-readable storage medium is provided that hasstored thereon program code executable by a computer system. The programcode can comprise code that causes the computer system to receive, froma user, first information pertaining to an energy generation system tobe installed at a customer site; code that causes the computer system todetermine an electrical design for installing the energy generationsystem at the customer site, the determining being based on the firstinformation, second information retrieved from one or more external datasources, an electrical data model, and a decision tree modeling anelectrical design process; and code that causes the computer system togenerate an installation diagram illustrating the determined electricaldesign.

A further understanding of the nature and advantages of the embodimentsdisclosed herein can be realized by reference to the remaining portionsof the specification and the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified block diagram of a system environment inaccordance with an embodiment of the present invention.

FIG. 2 is a simplified block diagram of a computer system in accordancewith an embodiment of the present invention.

FIG. 3 is a flow diagram of a process for facilitating the electricaldesign of an energy generation system in accordance with an embodimentof the present invention.

FIG. 4 is a flow diagram of a process for receiving user inputpertaining to an electrical design in accordance with an embodiment ofthe present invention.

FIG. 5 is an example graphical user interface in accordance with anembodiment of the present invention.

FIGS. 6A through 6G are flow diagrams illustrating an example decisiontree in accordance with an embodiment of the present invention.

FIG. 7 is a flow diagram summarizing the decision tree processing ofFIGS. 6A-6G in accordance with an embodiment of the present invention.

FIG. 8 is an example installation diagram in accordance with anembodiment of the present invention.

DETAILED DESCRIPTION

In the following description, for purposes of explanation, numerousexamples and details are set forth in order to provide an understandingof embodiments of the present invention. It will be evident, however, toone skilled in the art that certain embodiments can be practiced withoutsome of these details, or can be practiced with modifications orequivalents thereof.

Embodiments of the present invention provide a computer-implemented toolfor facilitating the electrical design of an energy generation system.In one embodiment, the tool can be implemented as a standalone (e.g.,desktop) software application configured to run autonomously on or morecomputing devices. In another embodiment, the tool can be implemented asa distributed software application hosted on, e.g., a web or applicationserver. In operation, the tool can generate a graphical user interfaceconfigured to request, from a user, initial information pertaining to anenergy generation system to be installed at a customer site. Oncereceived, the tool can use the initial information, in conjunction withan electrical data model, a decision tree, and additional informationretrieved from one or more external data sources, to determine anelectrical design for installing the energy generation system at thecustomer site. An installation diagram can then be generated thatillustrates the determined electrical design.

With the foregoing features, there is no need for an experiencedengineer or system designer to manually select each electrical componentof a system installation, or manually determine how those componentsshould be interconnected. Instead, all or a part of this process can beautomated. Thus, embodiments of the present invention empower a widerange of users, regardless of their technical expertise or experience,to quickly and easily create an electrical system design.

Further, by relying on a standard electrical data model and byretrieving information from external data sources (such as AHJ, utility,and state databases), the tool described above can ensure that thegenerated electrical design conforms to the various electrical/buildingrequirements (e.g., NEC, AHJ regulations, etc.) that apply to thecustomer site.

Yet further, the installation diagram generated by the tool can beformatted in a manner that simplifies system installation and componentprocurement. For example, in one embodiment, direct current (DC)components of the system can be grouped on one side of the diagram andalternating current (AC) components can be grouped on the other side ofthe diagram, thereby allowing two installation crews to separate thediagram in half and work concurrently on the AC and DC sidesrespectively. In another embodiment, the diagram can include a bill ofmaterials (BOM) that lists the make and model of each electricalcomponent, as well as the wire sizes needed to interconnect thecomponents. Thus, all of the information needed to procure theelectrical components (and their interconnecting wires) from the supplychain can be gleaned directly from the diagram itself, rather than beingcollected from other sources/locations. In one embodiment, the BOMinformation can be included in metadata associated with the installationdiagram (in addition to being displayed on the diagram). Thisinformation can then be transferred directly into, e.g., an inventorymanagement system.

For purposes of illustration, several of the examples and embodimentsthat follow are described in the context of solar PV systems. However,it should be appreciated that embodiments of the present invention maybe applied to other type of energy generation systems (e.g., windturbine, solar-thermal, geothermal, biomass, hydropower, etc.). One ofordinary skill in the art will recognize various modifications,variations, and alternatives.

FIG. 1 is a simplified block diagram of a system environment 100according to an embodiment of the present invention. As shown, systemenvironment 100 includes a computing device 102 configured to execute acomputer-aided design (CAD) program 104. Computing device 102 is anend-user computing device, such as a desktop computer, a laptopcomputer, a personal digital assistant, a smartphone, a tablet, or thelike. CAD program 104 is a software application that enables thecreation of technical and engineering drawings. Examples of suchprograms include AutoCAD, TurboCAD, and so on. In a particularembodiment, CAD program 104 can be suitable for creating electricaldiagrams, such as one-line or three-line diagrams.

Computing device 102 is further configured to execute an electricaldesign module 106. In certain embodiments, electrical design module 106can be implemented as a plug-in to CAD program 104, and thus can run inthe context of program 104. In other embodiments, electrical designmodule 106 can be implemented as a separate program that is configuredto interface (either programmatically or via data/metadata) with CADprogram 104.

Electrical design module 106 can provide various functions forfacilitating the electrical design of an energy generation system. Forinstance, electrical design module 106 can present, to a user ofcomputing device 102, a graphical user interface 108 for enteringinitial information pertaining to the installation of an energygeneration system at a particular site. This information can include,e.g., site electrical requirements, main panel and utility meterinformation, and the like.

Upon receiving the initial information via GUI 108, electrical designmodule 106 can automatically determine an electrical design for theenergy generation system. As part of this processing, electrical designmodule 106 can interact with an electrical data model 110 and a decisiontree 112. Electrical data model 110 can correspond to a set of datastructures and/or rules that define how various electrical componentsphysically connect to each other. In certain embodiments, electricaldata model 110 can be configured to conform to one or more electricalstandards, such as the National Electric Code (NEC). Decision tree 112can model a prototypical electrical design process, and thus canexemplify the decision making flow that is typically followed by anexperienced engineer/system designer when creating an electrical systemdesign. For example, each node of decision tree 112 can correspond to adecision/question to be resolved with respect to the design, or acorresponding decision outcome. A given path through the tree can definea set of decision outcomes that delineate the content of the finalelectrical design.

In operation, electrical design module 106 can traverse decision tree112 and thereby determine, in view of electrical data model 110, whatelectrical components are needed to implement the energy generationsystem and how those components should be interconnected. To resolve thedecisions/questions presented in decision tree 112, electrical designmodule 106 can refer to the initial information received via graphicaluser interface 108, or retrieve additional information from one or moreexternal data sources 114 (e.g., AHJ database 116, utility database 118,state database 120, supply chain database 122, and otherapplications/databases 124). If a particular decision/question cannot beresolved in view of the initial information or the data stored inexternal data sources 114, electrical design module 106 can prompt theuser of computing device 102 to provide the requisite information.

Once the electrical design has been determined, electrical design module106 can generate (via CAD program 104) an installation diagramillustrating the design. The installation diagram can then be used forvarious purposes, such as system installation, component procurement,permit approval, utility rebate submissions, and more.

It should be appreciated that system 100 is illustrative and is notintended to limit embodiments of the present invention. For example,although external data sources 114 are depicted as being remote fromcomputing device 102, in alternative embodiments one or more of datasources 114 may be stored locally on computing device 102. Further,although CAD program 104 and electrical design module 106 are shown asrunning on the same physical machine (i.e., computing device 102), oneof ordinary skill in the art will appreciate that program 104 and module106 can run on separate machines. Yet further, the various componentsdepicted in system 100 can have other capabilities or include othersubcomponents that are not specifically described. One of ordinary skillin the art will recognize many variations, modifications, andalternatives.

FIG. 2 is a simplified block diagram of a computer system 200 accordingto an embodiment of the present invention. In one embodiment, computersystem 200 can be used to implement computing device 102 of FIG. 1. Asshown in FIG. 2, computer system 200 can include one or more processors202 that communicate with a number of peripheral devices via a bussubsystem 204. These peripheral devices can include a storage subsystem206 (comprising a memory subsystem 208 and a file storage subsystem210), user interface input devices 212, user interface output devices214, and a network interface subsystem 216.

Bus subsystem 204 can provide a mechanism for letting the variouscomponents and subsystems of computer system 200 communicate with eachother as intended. Although bus subsystem 204 is shown schematically asa single bus, alternative embodiments of the bus subsystem can utilizemultiple busses.

Network interface subsystem 216 can serve as an interface forcommunicating data between computer system 200 and other computersystems or networks. Embodiments of network interface subsystem 216 caninclude, e.g., an Ethernet card, a Wi-Fi and/or cellular adapter, amodem (telephone, satellite, cable, ISDN, etc.), digital subscriber line(DSL) units, and/or the like.

User interface input devices 212 can include a keyboard, pointingdevices (e.g., mouse, trackball, touchpad, etc.), a scanner, a barcodescanner, a touch-screen incorporated into a display, audio input devices(e.g., voice recognition systems, microphones, etc.) and other types ofinput devices. In general, use of the term “input device” is intended toinclude all possible types of devices and mechanisms for inputtinginformation into computer system 200.

User interface output devices 214 can include a display subsystem, aprinter, a fax machine, or non-visual displays such as audio outputdevices, etc. The display subsystem can be a cathode ray tube (CRT), aflat-panel device such as a liquid crystal display (LCD), or aprojection device. In general, use of the term “output device” isintended to include all possible types of devices and mechanisms foroutputting information from computer system 200.

Storage subsystem 206 can include a memory subsystem 208 and a file/diskstorage subsystem 210. Subsystems 208 and 210 represent non-transitorycomputer-readable storage media that can store program code and/or datathat provide the functionality of embodiments of the present invention.

Memory subsystem 208 can include a number of memories including a mainrandom access memory (RAM) 218 for storage of instructions and dataduring program execution and a read-only memory (ROM) 220 in which fixedinstructions are stored. File storage subsystem 210 can providepersistent (i.e., non-volatile) storage for program and data files, andcan include a magnetic or solid-state hard disk drive, an optical drivealong with associated removable media (e.g., CD-ROM, DVD, Blu-Ray,etc.), a removable flash memory-based drive or card, and/or other typesof storage media known in the art.

It should be appreciated that computer system 200 is illustrative andnot intended to limit embodiments of the present invention. Many otherconfigurations having more or fewer components than system 200 arepossible.

FIG. 3 illustrates a process 300 that can be carried out by electricaldesign module 106 of FIG. 1 for facilitating the electrical design of anenergy generation system according to an embodiment of the presentinvention. At block 302, electrical design module 106 can receive, froma user via graphical user interface 108, first information pertaining toan energy generation system to be installed at a customer site. In oneembodiment, the first information can include various parameters thatare specific to the installation site, such as whether certainelectrical components are required (per AHJ/utility/state regulations),main panel information, utility meter information, groundingconfiguration, etc. The first information can also include informationabout certain core components of the system (e.g., energy generationcomponents such as PV modules, PV inverters, etc.).

In some cases, a portion (or all) of the initial information may beavailable from one or more external data sources (e.g., data sources 114of FIG. 1). In these situations, electrical design module 106 canautomatically retrieve this information from data sources 114 prior topresenting graphical user interface 108 to the user, and canpre-populate the data entry fields of interface 108 with the retrievedinformation (as, e.g., “default” values). In some embodiments, thedefault values may be displayed as read-only values in interface 108,thereby preventing the user from making any changes. In otherembodiments, the default values may be modifiable, thereby enabling theuser to override the defaults with alternative values.

At block 304, electrical design module 106 can automatically determinean electrical design for installing the energy generation system at thecustomer site based on the first information received at block 302,second information retrieved from external data sources 114, electricaldata model 110, and decision tree 112. As noted with respect to FIG. 1,electrical data model 110 can comprise a collection of data structuresand/or rules defining how various electrical components physicallyconnect with each other. Further, decision tree 112 can model aprototypical electrical design process, where each node in the treecorresponds to a decision/question to be resolved with respect to theelectrical design, or a corresponding decision outcome. As part of theprocessing of block 304, electrical design module 106 can traverse thenodes of decision tree 112 such that a path of decision outcomes isdefined. Electrical design module 106 can then determine, based on thedecision outcomes and electrical data model 110, the content of theelectrical design (i.e., the electrical components to be included in thedesign and the manner in which the components should be interconnected).

To resolve the decisions/questions encountered when traversing decisiontree 112, electrical design module 106 can consult the first informationreceived at block 302. If the necessary information was not provided atblock 302, electrical design module can automatically attempt toretrieve it from one or more external data sources 114. In this manner,electrical design module 106 can minimize the need for further userinput when generating the electrical design.

By way of example, assume a decision node of decision tree 112 requiresinformation regarding whether rooftop DC disconnects are required for agiven customer site. If this requirement information was not received aspart of the first information of block 302, electrical design module 106can attempt to retrieve it from one or more of external data sources114. In this example, such a requirement (if it exists) would likely bestored in AHJ database 116 and/or state database 120. If, for whateverreason, the requirement information cannot be found in data sources 114,electrical design module 106 can prompt the user (via GUI 108) for ananswer.

Once the electrical design has been determined per block 304, electricaldesign module 106 can generate, via CAD program 104, an installationdiagram illustrating the determined design (block 306). In a particularembodiment, the installation diagram can be formatted as an electricalthree-line diagram, with appropriate indicia illustrating the electricalcomponents of the system and the connections between the components.

The diagram generated at block 306 can be used by a number of differententities for different purposes. For example, in one embodiment, thediagram can be used by one or more installation crews for constructingthe system at the customer site. In another embodiment, the diagram canbe submitted to local building authorities to facilitate permitapproval. In yet another embodiment, the diagram can be submitted to autility company for energy rebate qualification.

In a particular embodiment, the diagram can include a bill of materialscomprising, e.g., the make/model number of each component and the wiresizes needed for the component connections. In these embodiments, thediagram can be provided to, e.g., a supply chain department to procurethe necessary components for installation.

Additional details regarding the processing performed at each of theblocks of FIG. 3, along with other features and advantages of thepresent invention, are provided in the sections below.

Receiving Initial Information

As discussed at block 302 of FIG. 3, electrical design module 106 cancollect/receive initial information regarding an energy generationsystem to be installed at a customer site. The type of informationcollected at this step may vary depending on the type of system beinginstalled. FIG. 4 illustrates an exemplary process 400 for performingthis collection step with respect to a solar PV system according to anembodiment of the present invention.

At block 402, electrical design module 106 can generate a GUI comprisingfields for inputting information regarding the DC and AC components of aPV system. An example of such a GUI 500 is depicted in FIG. 5. In theembodiment of FIG. 5, sections 502, 504, and 506 of GUI 500 correspondto the DC side of the PV system, and sections 508, 510, and 512 of GUI500 correspond to the AC side of the PV system.

The remaining blocks of process 400 describe the specific types ofinformation that may be collected via GUI 500 with respect to the PVsystem. For instance, at block 404, electrical design module 106 canreceive, via GUI 500, a selection of a PV module and a corresponding setof module strings. This information can be entered at, e.g., section 502of GUI 500. As shown in FIG. 5, the “Add String” button can be used todefine multiple strings for a single module type.

At block 406, electrical design module 106 can determine a list ofcompatible PV inverters for the set of strings entered at block 404.Such a list is illustrated in user interface 500 at section 504. Asshown, each inverter can be color-coded to represent the percentage ofits capacity that would be used for the string set. In addition, thiscapacity percentage can be displayed in text next to the inverter name.In certain embodiments, the list of inverters determined at block 406can be retrieved from a component supply chain database (e.g., database122 of FIG. 1). Further, the list can be filtered in view of a number ofdifferent criteria, such as such as supply chain availability/demand,cost, location of the customer site, customer preference, and the like.Thus, in these embodiments, electrical design module 106 can tailor theinverter list to only include specific models that it deems to beappropriate (based on cost, availability, etc.) for the current systeminstallation.

Once the list of inverters has been presented to the user, electricaldesign module 106 can receive, at block 408, a selection of a particularinverter from the list (via the “Add Inverter to System” button shown insection 504 of FIG. 5). If the user determines that additional stringsand inverters need to be added to the system (block 410), process 400can return to block 404. Otherwise, process 400 can proceed to block412.

Blocks 412 through 418 are steps for receiving information regarding thebalance of the DC and AC components of system. For example, at block412, electrical design module 106 can receive information regardingrequired DC disconnects and combiner boxes (via section 506 of GUI 500).And at blocks 414-418, electrical design module 106 can receiveinformation regarding the main panel/utility meter, AC disconnects andmonitoring options, and grounding options (via sections 508, 510, and512 of GUI 500 respectively).

In certain embodiments, some (or all) of the information described withrespect to blocks 412-418 may be available in one or more of externaldata sources 114, such as AHJ database 116, utility database 118, statedatabase 120, and so on. In these embodiments, electrical design module106 can retrieve the information from data sources 114 and pre-populatethe retrieved information in the fields of GUI 500 as default values. Inone embodiment, the default values may be displayed as read-only valuesin GUI 500, thereby preventing the user from making any changes. Inanother embodiment, the default values may be modifiable, therebyenabling the user to override the defaults with alternative values.

Generating the Electrical Design

Once the various sections of GUI 500 have been filled in, the user canactivate the “Draw” button (514) of GUI 500 to begin the electricaldesign generation process. As described with respect to block 304 ofFIG. 3, this process can include traversing a decision tree (e.g., 112of FIG. 1) that models the decision making flow for generating theelectrical design. FIGS. 6A through 6G illustrate an example decisiontree (comprising flow diagrams 600-660) for generating the electricaldesign of a PV system according to an embodiment of the presentinvention. It should be appreciated that the decision tree of FIGS.6A-6G is provided for illustration purposes only, and is not intended tolimit embodiments of the present invention. For example, althoughcertain brands of PV inverters are referenced in the decision tree, oneof ordinary skill in the art will recognize that other brands andcorresponding decision paths may be supported.

While traversing the decision tree of FIGS. 6A-6G, electrical designmodule 106 can refer to the initial information collected via userinterface 500, as well as query additional information from externaldata sources 114, to answer the various questions that may beencountered (e.g., “Is a DC disconnected required?” or “Is a separateGrounding Electrode Conductor (GEC) required?”). Any information thatcannot be determined from the initial information or the data inexternal data sources 114 can be directly requested (via, e.g., a dialogbox or other input interface) from the user. Once a path has beendefined through the decision tree, electrical design module 106 canapply an electrical data model (e.g., 110 of FIG. 1) to determine howthe various electrical components of the design should be physicallyconnected. This can ensure that the resulting design is compliant withall appropriate standards and regulations.

FIG. 7 illustrates a process 700 that summarizes, at a high level, thedecision making process carried out by the decision tree of FIGS. 6A-6E.At block 702, the decision tree can enter a loop for each PV inverterselected at block 408 of FIG. 4. At blocks 704-708, the decision treecan resolve the DC side of the PV system. In particular, the decisiontree can retrieve the PV module strings associated with the PV inverter,determine the number and type of components that should be inserted onthe DC side of the PV inverter (e.g., DC disconnects, combiner boxes,etc.), and determine the interfaces and wire sizes to be used betweenthe DC components. Blocks 704-708 can be repeated until all of the PVinverters in the system have been processed (block 710).

At blocks 712 and 714, the decision tree can resolve the AC side of thePV system. In particular, at block 712, the decision tree can determinethe number and types of components that should be inserted on the ACside of the PV inverters (e.g., AC disconnects, PV meters, etc.). And atblock 714, the decision tree can determine the interfaces and wire sizesto be used between the AC components.

Once the DC and AC components of the system have been resolved, thedecision tree can determine the appropriate method for interconnectingthe PV system (in particular, the PV inverters) to the utility grid viathe site's main panel (block 716). This will vary depending on thelayout of the site and the make and model of the main panel.

Finally, the decision tree can determine the grounding configuration forthe system (block 718).

The Installation Diagram

FIG. 8 is an installation diagram 800 for a PV system that may begenerated by electrical design module 106 (via CAD program 104)subsequently to the decision tree processing of FIG. 7. As shown,diagram 800 depicts the various electrical components of the PV system,as well as the interconnections/conduits between each component. Forexample, on the DC side, PV module strings 802 are connected to DCcombiner box 804. DC combiner box 804 is, in turn, connected to two DCdisconnects (rooftop disconnect 806 and disconnect 808), which lead toPV inverter 810. On the AC side, PV inverter 810 is connected to metersocket 812, which is connected to main service panel 814 via ACdisconnect 816. Note that diagram 800 specifically illustrates how thePV inverter power lines are tied into the breakers of main panel 814.

In the embodiment of FIG. 8, diagram 800 is organized such that the DCcomponents of the system (802-810) are grouped on the right side of thediagram, while the AC components of the system (812-816) are grouped onthe left side of the diagram. This can facilitate installation of thecomponents at the customer site. For instance, in many cases, oneinstallation crew will work on installing the DC side of the systemwhile another installation crew will simultaneously work on installingthe AC side of the system. By organizing diagram 800 in the mannershown, the diagram can be conveniently split in half and provided to theappropriate crew for installation.

Further, diagram 800 includes, along the bottom half, a BOM that liststhe make and model numbers of the components depicted in the diagram, aswell information regarding the wires needed to connect the components(e.g., wire size and type). Thus, all of the information needed toprocure the electrical components (and their interconnecting wires) fromthe supply chain can be gleaned directly from the diagram itself, ratherthan being collected from other sources/locations. As shown, eachsection of the BOM is marked by a designator (A, B, C, etc.) indicatingwhich component that section maps to in the illustration above. As notedpreviously, the BOM information can be included in metadata associatedwith diagram 800 (in addition to being displayed on the diagram). Thisinformation can then be transferred directly into, e.g., an inventorymanagement system.

The above description illustrates various embodiments of the presentinvention along with examples of how aspects of the present inventionmay be implemented. The above examples and embodiments should not bedeemed to be the only embodiments, and are presented to illustrate theflexibility and advantages of the present invention as defined by thefollowing claims. For example, although certain embodiments have beendescribed with respect to particular process flows and steps, it shouldbe apparent to those skilled in the art that the scope of the presentinvention is not strictly limited to the described flows and steps.Steps described as sequential may be executed in parallel, order ofsteps may be varied, and steps may be modified, combined, added, oromitted. As another example, although certain embodiments have beendescribed using a particular combination of hardware and software, itshould be recognized that other combinations of hardware and softwareare possible, and that specific operations described as beingimplemented in software can also be implemented in hardware and viceversa.

The specification and drawings are, accordingly, to be regarded in anillustrative rather than restrictive sense. Other arrangements,embodiments, implementations and equivalents will be evident to thoseskilled in the art and may be employed without departing from the spiritand scope of the invention as set forth in the following claims.

1.-20. (canceled)
 21. A method comprising: receiving, by a computersystem from a user, information pertaining to a solar photovoltaic (PV)energy generation system; determining, by the computer system, a list ofPV inverters compatible with the information; determining, by thecomputer system, a first set of electrical components compatible witheach inverter of the list of PV inverters by utilizing a first portionof a decision process comprising a first series of interrelated queriesorganized in a logical flow and specific to determining the first set ofelectrical components; determining, by the computer system, a second setof electrical components compatible with each inverter of the list of PVinverters by utilizing a second portion of the decision processcomprising a second series of interrelated queries organized in alogical flow and specific to determining the second set of electricalcomponents; determining, by the computer system, electrical designs foreach PV inverter comprising the corresponding first and second set ofelectrical components; and generating, by the computer system, aninstallation diagram illustrating at least one of the determinedelectrical designs.
 22. The method of claim 21 wherein the first set ofelectric components comprise one or more direct current (DC) components.23. The method of claim 21 wherein the second set of electric componentscomprise one or more alternating current (AC) components.
 24. The methodof claim 21 wherein the information includes PV information pertainingto PV module strings.
 25. The method of claim 21 wherein a portion ofthe information is populated with defaults received from one or moreexternal data sources.
 26. The method of claim 25 wherein the one ormore external data sources are selected from a group consisting of: anAuthority Having Jurisdiction (AHJ) database, a utility database, astate database, and a component supply chain database.
 27. The method ofclaim 21 wherein the first and second series of interrelated queriesdetermine how the first and second set of electrical components shouldbe interconnected.
 28. The method of claim 21 wherein determining theelectrical designs for each PV inverter is based on the first and secondset of electric components, and an electrical data model.
 29. The methodof claim 28 wherein the electrical data model comprises a plurality ofrules indicating how electrical components of the energy generationsystem may be interconnected, the plurality of rules conforming to theNational Electric Code (NEC).
 30. The method of claim 21 whereindetermining the electrical designs for each PV inverter comprisestraversing nodes of a decision tree, each node representing a decisionor a decision outcome.
 31. The method of claim 30 wherein the methodfurther comprises, for a given node of the decision tree representing adecision: determining whether the decision can be automaticallydetermined by the computer system based on the information; and when thequestion cannot be automatically determined based on the information,prompting the user for an answer.
 32. The method of claim 21 wherein theinstallation diagram includes a bill of materials.
 33. The method ofclaim 32 wherein the bill of materials identifies make and model numbersfor each electrical component of the energy generation system.
 34. Themethod of claim 33 wherein the bill of materials further identifiessizes of wires needed to interconnect the electrical components.
 35. Themethod of claim 21 further comprising outputting the installationdiagram to the user.
 36. A system comprising: a processor configured to:receive, by a computer system from a user, information pertaining to asolar photovoltaic (PV) energy generation system; determine, by thecomputer system, a list of PV inverters compatible with the information;determine, by the computer system, a first set of electrical componentscompatible with each inverter of the list of PV inverters by utilizing afirst portion of a decision process comprising a first series ofinterrelated queries organized in a logical flow and specific todetermining the first set of electrical components; determine, by thecomputer system, a second set of electrical components compatible witheach inverter of the list of PV inverters by utilizing a second portionof the decision process comprising a second series of interrelatedqueries organized in a logical flow and specific to determining thesecond set of electrical components; determine, by the computer system,electrical designs for each PV inverter comprising the correspondingfirst and second set of electrical components; and generate, by thecomputer system, an installation diagram illustrating at least one ofthe determined electrical designs.
 37. The system of claim 36 whereinthe processor is further configured to output the installation diagramto the user.
 38. A method comprising: determining, by a computer system,a set of direct current (DC) components compatible with an inverter byutilizing a first portion of a decision process comprising a firstseries of interrelated queries organized in a logical flow and specificto determining the set of DC components; determining, by the computersystem, a set of alternating current (AC) components compatible with theinverter by utilizing a second portion of the decision processcomprising a second series of interrelated queries organized in alogical flow and specific to determining the set of AC components;determining, by the computer system, electrical designs for the invertercomprising the corresponding set of AC components and set of DCcomponents; and generating, by the computer system, an installationdiagram illustrating at least one of the determined electrical designs.39. The method of claim 38 wherein determining the electrical designsfor each PV inverter is based on the first and second set of electriccomponents, and an electrical data model.
 40. The method of claim 39wherein the electrical data model comprises a plurality of rulesindicating how electrical components of the energy generation system maybe interconnected, the plurality of rules conforming to the NationalElectric Code (NEC).